Packet switch networks are now being used to transport streaming media, such as video or audio from a media server to multiple receivers, such as computer terminals and Set Top Boxes (STBs). However, packet switched networks typically use a best effort transport that may significantly delay or drop some packets. Retransmission schemes have been designed to retransmit the dropped or delayed media packets to receivers but may be inadequate to resolve or deal with certain packet switched network outages.
For example, media packets may be multicast by a media server to multiple different receivers. The packet switched network then automatically branches the multicast packets along different network paths to the different receivers in an associated multicast group. Problems arise when the multicast packets are lost upstream of branch points near the leaves of the delivery tree where the receivers are. For example, the upstream packet loss may cause a significant fraction of the receivers to send Negative ACKnowledgmets (NACKs) back to the media stream repair point. These numerous returned NACKs, all reporting the same loss, use up network bandwidth and can overwhelm the media stream repair point.